The protagonist of this novel is Owen Mackenzie, a character who earned a degree in mathematics in the 1950's and went on to work with computers. His first lover, as well, was a mathematician. They have "mathematical conversations" such as (quoted from Villages) 'But Owen dear,' Phyllis said, 'the antinomies  the paradoxes  undermine
classical logic, but the way they have to be phrased brings us to symbolic
logic, which brings in Boolean math and the Turing machine and algorithms.'

Even when Phyllis leaves the picture, she does so in a mathematical way:
(quoted from Villages)
God killed Phyllis, as a favor to him: from this blasphemous thought he seeks to shield himself with the fancy that Phyllis, the beautiful math major, had crossed herself out the way a redundant term is dropped from the denominator and the numerator of a complex fraction.

For those interested in computers, there are also many computer references peppered throughout the book. However, the primary focus remains, as always in Updike's writings, on the sex.
Thanks to Peter Freyd for sending me a review of this book.
